| 摘要 |
An apparatus for automatically closing a bottom safety valve in a pumped oil well in case of a cessation of pumping, and reopening the valve when pumping resumes. A conventional valve pump is installed in the production tube. A channel, which is connected to the production tube, passes through the valve body, and is blocked by a controllable flap. The valve body also contains a second channel, the two channels communicating by means of a cavity which is located upstream of the flap. A push rod slidably retained in the second channel is actuated by a piston for opening and closing the flap. A conduit connects the downstream portion of the production tube to an admission chamber and thereby transmits pressure to the piston; such that, when the downstream pressure of the valve pump is greater than that at the bottom of the well, the flap remains open; and when the difference in the pressures is reversed, the push rod causes the flap to close.
|
